Define the following terms:
$(i)$ Mole fraction $(ii)$ Molality $(iii)$ Molarity $(iv)$ Mass percentage

(N/A) $(i)$ Mole Fraction: It is defined as the ratio of the number of moles of the solute to the total number of moles in the solution. If $n_A$ is the number of moles of solute and $n_B$ is the number of moles of solvent,then the mole fraction of solute $(X_A)$ is given by:
$X_A = \frac{n_A}{n_A + n_B}$
$(ii)$ Molality $(m)$: It is defined as the number of moles of solute present in $1 \ kg$ $(1000 \ g)$ of solvent.
$m = \frac{\text{Number of moles of solute}}{\text{Mass of solvent in kg}}$
$(iii)$ Molarity $(M)$: It is defined as the number of moles of solute present in $1 \ L$ of solution.
$M = \frac{\text{Number of moles of solute}}{\text{Volume of solution in litres}}$
$(iv)$ Mass Percentage: It is defined as the mass of solute in grams present in $100 \ g$ of solution.
$\text{Mass percentage} = \frac{\text{Mass of solute}}{\text{Mass of solution}} \times 100$